This study will investigate the behavior of preschool children who had undergone general surgery during early infancy and will correlate the behavioral outcomes with clinical perioperative variables.

Several epidemiologic and observational studies found the relation between surgery in childhood and neurodevelopmental features in later life. However, these studies are criticized for retrospective design, non homogenous population, social confounders, diversity of surgical procedures and anesthetic management.

Monitoring of neurological function has become standard during surgical procedures at risk for neuronal injury (e.g. cardiac surgery). There is also some data on possible predictive value of certain methods of neuromonitoring (such as cerebral near infrared spectroscopy (NIRS)) for neurodevelopmental outcome.

General neonatal/infant surgery and the whole perioperative period carry the risk of significant physiologic disturbances, which may affect cerebral perfusion, oxygenation or metabolism. This study is the continuum of prospective observational trial, which investigated the value of the neuromonitoring measures in neonates and young infants undergoing general surgery. The present study will apply the behavioral assessment of these patients who are now between 2 and 5 years of age.

Inclusion Criteria:

• children, who had undergone general surgery for congenital anomalies or disease from birth until 93 days of age at a single University hospital
• general anesthesia with inhalational anesthetic was applied during surgery
• artificial lung ventilation was applied during anesthesia
• NIRS values were recorded throughout anesthesia
• serum concentrations of brain specific proteins were obtained during perioperative period

Exclusion Criteria:

• children, who had undergone cardiac, neurosurgical, ear, nose and throat or eye surgery from birth until 93 days of age
• general anesthesia without tracheal intubation was applied
• local or combined local/general anesthesia was applied

Children, aged 1.5-5 years, who had undergone general abdominal, thoracic, genitourinary surgery until 93 days of life in a single University hospital and were given standard inhalational general anesthesia with tracheal intubation and measures for neuromonitoring such as cerebral NIRS and measurement of brain specific proteins during perioperative period was applied.